Diazadithia[7]helicenes: Synthetic Exploration, Solid‐State Structure, and Properties. Issue 36 (22nd July 2013)

• Record Type: Journal Article
• Authors: Waghray, Deepali; Cloet, Arvid; Van Hecke, Kristof; Mertens, Stijn F. L.; De Feyter, Steven; Van Meervelt, Luc; Van der Auweraer, Mark; Dehaen, Wim
• Is Part Of: Chemistry. Volume 19:Issue 36(2013)
• Page Start: 12077
• Page End: 12085
• Publication Date: 2013-07-22
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201300843
• Languages: English
• ISSNs: 0947-6539

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>Diazadithia[7]helicenes were synthesized from the readily available building block ethyl 7‐chloro‐8‐formylthieno[3, 2‐<italic>f</italic>]quinoline‐2‐carboxylate by a Wittig reaction–photocyclization strategy. The helicene core was functionalized by nucleophilic aromatic substitution with a variety of nucleophiles (e.g., O‐, N‐, and C‐centered) and palladium‐catalyzed reactions such as Suzuki coupling and Buchwald–Hartwig amination. Racemization studies confirmed that the enantiopure forms of these [7]helicenes are conformationally stable compared to their lower analogues. The solid‐state structures of the novel diazadithia[7]helicenes were determined by single‐crystal X‐ray diffraction. The crystal structures of these azathia[7]helicenes show columnar stacking in antiparallel fashion. The HOMO–LUMO gaps of the new compounds were determined on the basis of electrochemical and optical measurements.</p> </abstract>